Commit-ID: 73fdeb66592ee80dffb16fb8a9b7378a00c1a826 Gitweb: http://git.kernel.org/tip/73fdeb66592ee80dffb16fb8a9b7378a00c1a826 Author: Huaitong Han <huaitong....@intel.com> AuthorDate: Mon, 31 Aug 2015 16:21:02 +0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 13 Sep 2015 11:27:23 +0200
perf/x86/intel/pt: Fix KVM warning due to doing rdmsr() before the CPUID test If KVM does not support INTEL_PT, guest MSR_IA32_RTIT_CTL reading will produce host warning like "kvm [2469]: vcpu0 unhandled rdmsr: 0x570". Guest can determine whether the CPU supports Intel_PT according to CPUID, so test_cpu_cap function is added before rdmsr,and it is more in line with the code style. Signed-off-by: Huaitong Han <huaitong....@intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Jiri Olsa <jo...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephane Eranian <eran...@google.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Vince Weaver <vincent.wea...@maine.edu> Cc: a...@kernel.org Link: http://lkml.kernel.org/r/1441009262-9792-1-git-send-email-huaitong....@intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/cpu/perf_event_intel_pt.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index 4216928..868e119 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -139,9 +139,6 @@ static int __init pt_pmu_hw_init(void) long i; attrs = NULL; - ret = -ENODEV; - if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) - goto fail; for (i = 0; i < PT_CPUID_LEAVES; i++) { cpuid_count(20, i, @@ -1130,6 +1127,10 @@ static __init int pt_init(void) int ret, cpu, prior_warn = 0; BUILD_BUG_ON(sizeof(struct topa) > PAGE_SIZE); + + if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) + return -ENODEV; + get_online_cpus(); for_each_online_cpu(cpu) { u64 ctl; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
